Existing electrical connectors are assemblies of pins, latching elements, support elements, electrical conduction elements, and housing. These connectors are typically used to provide electrical signal conductivity from one printed circuit board to another. FIG. 1 illustrates a typical prior art electrical backplane connection scheme for coupling electrical signals between high speed backplanes and daughter cards via conventional electrical connectors 26 shown in FIG. 2. Backplanes are one form of printed circuit board. High speed backplane 50 is typically coupled via one or more electrical connectors 26 to remote semiconductor devices on one or more printed circuit boards, such as daughter cards 10 or line cards 30. Electrical connector 26, consisting of a mother board or backplane side connector 20 with a corresponding mating connector 16 on the daughter board. Connectors 20 and 16 typically consist of passive, non-active components that conducts electrical signals, such as originating from one daughter card 10 via electrical connector 16, which is mated to backplane 50 via electrical connector 20, the conducted electrical signals is then again transmitted down one or more electrical conductive paths 52 on mother board or backplane 50 to another destination printed circuit board 30, again via similar electrical connectors 20 and 16. The backplane conduction path 52 is depicted as a point to point connection. However, any backplane topology may also be applied to this invention such as multipoint, mesh, and star topology.
Prior art scheme with conventional connectors 16 and 20 require semiconductor device 12 on daughter card 10 to transmit electrical signal across the entire transmission path 54 ending at the receiving semiconductor device 32 on daughter card 30. This requires driver 13 (FIG. 2) in semiconductor device 12 on daughter card 10 to handle reflections caused by discontinuities (vias, etc.) in the signal path, cross talk caused by the first set of electrical connector 26, and signal attenuation due to the entire PCB transmission paths 14, 52, and 34. Driver 13 compensates for any of adverse transmission effects along this path typically results in compounded effects, such as increasing amplitude to compensate for signal attenuation may also increase cross talk. Receiver 33 on daughter card device 32 must also correctly interpret the electrical signals after traversing the entire transmission path 54.
Electrical connectors 16 and 20 receive electrical signals, and serve as an electrical conduction means for the electrical signals they conduct. Connectors 16 and 20 are constructed and designed to provide maximum conduction with minimum perturbation to the electrical signals conducted. Semiconductor devices 12 and 32 on daughter cards 10 and 30, respectively, in effect drive the electrical signals with some degrading effects from the electrical connectors 16 and 20. However, as electrical signal frequency increases into and beyond Gigabits and Giga Hertz domain as in increasingly high speed applications, the adverse effects of the electrical connectors 16 and 20 to transmission path 54 become critical. Some of the resulting adverse effects of electrical connectors 16 and 20 are cross talk, signal attenuation, and reflection, which no longer are trivial effects at these higher frequencies. The electrical signals at high speeds, e.g. 1 Gbps to 10 Gbps and beyond have more stringent AC requirements. The additional complexity from the increased stringent requirements along with the increasing adverse effects from the electrical connectors limits achievable data rates across the backplane and subsequently the entire system.
There is therefore a need to provide an improved electrical connector for high-speed electrical backplane applications that minimizes the adverse effects of cross talk, signal attenuation and reflection while leverage more cost effective materials, e.g. FR4, to achieve the higher data rates.